The Supreme Court of the United States (SCOTUS) consists of nine really old people who sit in judgment on whether or not laws (local, state, or federal) are in compliance with the USConstitution and have the final say on how the federal laws are to be interpreted. This power of the courts is called judicial review, and the precedent for its use by the SCOTUS was established in the 1802 case Marbury v. Madison.

The members, or "associate justices," are appointed by the President, and take office upon confirmation by the Senate (which is not always forthcoming in today's political climate).

One member serves as "chief justice," who, although still only having one vote on cases, has the interesting and sometimes important power to assign the writing of majority decisions (when they are in the majority) to one of the associates. This can be used to influence the exact nature of a decision — the chief justice might vote with a four justice minority (or more importantly, a five justice majority) in order to assign the decision writing to a justice with a weaker stand than the other members of the majority.

In practice, the most powerful member of the Court is rarely the Chief Justice but the one or two "moderate" members who are very often the swing vote on contentious issues. Anthony Kennedy is purported to be one such justice on the current Court (see below).

Anthony Kennedy: Nominated by Ronald Reagan, Kennedy is most definitely not one of "those" Kennedys. Said to be the court's swing vote, being the member who sits ideologically between the four left wing members (see below) and the right-wing "Four Horsemen." In practice, though, Kennedy is a fairly reliable vote for conservative ideology.[5] Incidentally, should he vote with the liberals (with no others defecting), he chooses who will write the majority opinion as he is senior to all those in the liberal wing.

Of the US states, 48 have a single court of last resort (called the Court of Appeals in Maryland and New York, the Supreme Judicial Court in Maine and Massachusetts, and the Supreme Court elsewhere). Oklahoma and Texas each have two courts of last resort, a Supreme Court for civil matters and a Court of Criminal Appeals for criminal matters. A state supreme court's interpretation of its state constitution and its state statutory and common law is final and is binding on both lower state courts and all federal courts, including (at least in theory) the Supreme Court of the United States. Federal courts may still adjudicate whether a state's constitution and laws conflict with the U.S. Constitution or federal law.

Also, many other countries have similar ultimate judicial arbiters with one name or another. They tend to be comparatively functional and non-partisan.

↑ During his infamous 2008 interview on CBS 60 Minutes Antonin Scalia claimed that torture may be cruel and unusual, but it is not punishment because the prisoner has not yet been convicted of a crime. At that point it's just interrogation. Hear that, all you nightstick happy cops out there? You can beat the hell out of a suspect before he/she has been convicted, but not after!